Topsoil Calculator
Adding topsoil is essential for establishing new lawns, raising low garden beds, and improving soil quality. This topsoil calculator determines how many cubic yards and 1-cubic-foot bags you need based on your area and desired depth.
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Formula
Volume (cu yd) = L × W × (D/12) / 27
Length and width in feet, depth in inches converted to feet by dividing by 12. Dividing by 27 converts cubic feet to cubic yards. One cubic yard equals 27 cubic feet, so multiply cubic yards by 27 to get the number of 1-cubic-foot bags needed.
How to use the Topsoil Calculator
- 1
Enter your length (ft)
Value should be in ft.
- 2
Enter your width (ft)
Value should be in ft.
- 3
Enter your depth (in)
Value should be in in.
- 4
Read your results instantly
Results update in real time as you type.
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How Much Topsoil Does a Lawn Need?
For seeding a new lawn, you need at least 4–6 inches of quality topsoil over the entire area. For overseeding or topdressing an existing lawn, 1/4 to 1/2 inch of topsoil or compost is sufficient. For raised garden beds, 6–12 inches of topsoil amended with compost provides excellent growing conditions. Poor native soil should be amended or replaced to a depth where roots will actively grow.
What Makes Good Topsoil?
Quality topsoil should be dark in color, have an earthy smell, and contain adequate organic matter. It should crumble easily when squeezed, not be solid clay or pure sand. Screened topsoil is preferable — it has been run through a screen to remove rocks and debris. For optimal lawn and garden results, blend topsoil with 20–30% compost to improve drainage, water retention, and nutrient content.
Tips & Insights
Test Before You Top-Dress
Have your existing soil tested before adding topsoil. A $15–$30 soil test from your local cooperative extension tells you exactly what nutrients and pH adjustments are needed, preventing wasted amendment.
Order Bulk for Large Areas
Bulk topsoil is dramatically cheaper than bagged. A cubic yard of bulk topsoil costs $20–$60; buying that same volume in 1-cubic-foot bags would cost $60–$120. For any project over 2 yards, order bulk.
Don't Mix With Clay Subgrade
Rototilling topsoil into hard clay can make drainage worse by creating a 'flowerpot effect.' Instead, break up clay with a subsoiler or add a deep layer of topsoil on top without mixing.
Worked Examples
New Lawn Area
18.52 cubic yards — order 19 yards bulk to seed a 1,500 sq ft new lawn to 4-inch depth.
Raised Vegetable Bed
1.19 cubic yards — about 32 bags of 1-cu ft topsoil for a deep, productive garden bed.
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Frequently Asked Questions
How many cubic yards of topsoil do I need for a new lawn?
At 4-inch depth, you need 0.012 cubic yards per square foot. A 1,000-sq-ft lawn needs about 12.3 cubic yards. Use our calculator for any exact area.
What is the difference between topsoil and garden soil?
Topsoil is natural soil from the top layer of earth, screened to remove debris. Garden soil is a manufactured blend of topsoil, compost, and sometimes fertilizer. Garden soil works better in raised beds; topsoil is better for large in-ground areas.
How deep should topsoil be for grass?
Grass roots penetrate 4–6 inches. A minimum of 4 inches of quality topsoil is needed for healthy lawn establishment. More is always better for drought resistance and long-term performance.
How much does topsoil cost per yard?
Screened topsoil typically costs $15–$50 per cubic yard bulk, depending on region and quality. Premium blended topsoil-compost mixes can run $50–$100 per yard.
Should I till before adding topsoil?
For new lawn areas, lightly till the existing surface 1–2 inches to help the new topsoil bond rather than creating a distinct layer. For heavily compacted soil, deeper aeration or subsoil breaking is beneficial first.
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